ringbuffer.c

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/*-----------------------------------------------------------------------------------
                                       INCLUDE HEADE FILES
 ------------------------------------------------------------------------------------*/
#include "ringbuffer.h"
 
void ring_buffer_create(ring_buffer_t *rb, uint8_t *buffer, uint32_t size)
{
    if ((rb == NULL) || (buffer == NULL) || (size == 0)) {
        return;
    }
 
    rb->buffer     = buffer;
    rb->size       = size;
    rb->tail_index = 0;
    rb->head_index = 0;
    rb->rx_lock    = false;
}
 
 
void ring_buffer_queue(ring_buffer_t *rb, uint8_t data)
{
    /* Is buffer full? */
    if (ring_buffer_is_full(rb)) {
        /* Is going to overwrite the oldest byte */
        /* Increase tail index */
        rb->tail_index = ((rb->tail_index + 1) & (rb->size - 1));
    }
 
    /* Place data in buffer */
    rb->buffer[rb->head_index] = data;
 
    rb->head_index             = ((rb->head_index + 1) & (rb->size - 1));
}
 
void ring_buffer_queue_arr(ring_buffer_t *rb, uint8_t *data,
                           ring_buffer_size_t size)
{
    /* Add bytes; one by one */
    ring_buffer_size_t i;
    for (i = 0; i < size; i++) {
        ring_buffer_queue(rb, data[i]);
    }
}
 
ring_buffer_size_t ring_buffer_dequeue(ring_buffer_t *rb, uint8_t *data)
{
    if (ring_buffer_is_empty(rb)) {
        /* No items */
        return 0;
    }
 
    *data          = rb->buffer[rb->tail_index];
 
    rb->tail_index = ((rb->tail_index + 1) & (rb->size - 1));
    return 1;
}
 
ring_buffer_size_t ring_buffer_dequeue_arr(ring_buffer_t *rb, uint8_t *data,
                                           ring_buffer_size_t len)
{
    if (ring_buffer_is_empty(rb)) {
        /* No items */
        return 0;
    }
 
    unsigned char *data_ptr = data;
    ring_buffer_size_t cnt  = 0;
    while ((cnt < len) && ring_buffer_dequeue(rb, data_ptr)) {
        cnt++;
        data_ptr++;
    }
    return cnt;
}
 
 
ring_buffer_size_t ring_buffer_peek(ring_buffer_t *rb, uint8_t *data,
                                    ring_buffer_size_t index)
{
    if (index >= ring_buffer_num_items(rb)) {
        /* No items at index */
        return 0;
    }
 
    /* Add index to pointer */
    ring_buffer_size_t data_index = ((rb->tail_index + index) & (rb->size - 1));
    *data                         = rb->buffer[data_index];
    return 1;
}
 
extern inline ring_buffer_size_t ring_buffer_is_empty(ring_buffer_t *rb);
extern inline ring_buffer_size_t ring_buffer_is_full(ring_buffer_t *rb);
extern inline ring_buffer_size_t ring_buffer_num_items(ring_buffer_t *rb);